package OpenDis4Examples;
import java.io.*;
import java.net.*;
import java.util.*;
import edu.nps.moves.dis.*;
import edu.nps.moves.disutil.CoordinateConversions;
import edu.nps.moves.disutil.DisTime;
/**
* Creates and sends ESPDUs in IEEE binary format. Adapted from OpenDIS library
* example package edu.nps.moves.examples
*
* @author DMcG
*/
public class EspduSender
{
/** Default constructor */
public EspduSender()
{
// default constructor
}
/** Defining number of packets to send is superior to infinite loops
* which have possible hazard of unstoppably sending packets as a zombie process */
public static final int NUMBER_TO_SEND = 5; // 5000;
/** Type of network connection */
public enum NetworkMode {
/** Unicast network mode
* @see <a href="https://en.wikipedia.org/wiki/Unicast" target="_blank">https://en.wikipedia.org/wiki/Unicast</a> */
UNICAST,
/** Multicast network mode
* @see <a href="https://en.wikipedia.org/wiki/Multicast" target="_blank">https://en.wikipedia.org/wiki/Multicast</a> */
MULTICAST,
/** Broadcast network mode
* @see <a href="https://en.wikipedia.org/wiki/Broadcasting_(networking)" target="_blank">https://en.wikipedia.org/wiki/Broadcasting_(networking)</a> */
BROADCAST
};
/**
* Default multicast group address we send on.
*/
public static final String DEFAULT_MULTICAST_ADDRESS = "239.1.2.3";
/**
* Default multicast port used, matches Wireshark DIS capture default
* @see <a href="https://en.wikipedia.org/wiki/Port_(computer_networking)" target="_blank">https://en.wikipedia.org/wiki/Port_(computer_networking)</a>
*/
public static final int DEFAULT_MULTICAST_PORT = 3000;
/**
* Possible system properties, passed in via -Dattr=val networkMode:
* unicast, broadcast, multicast destinationIp: where to send the packet. If
* in multicast mode, this can be multicast. To determine broadcast
* destination IP, use an online broadcast address calculator, for example
* http://www.remotemonitoringsystems.ca/broadcast.php If in multicast mode,
* a join() will be done on the multicast address. port: port used for both
* source and destination.
*
* @param args command-line arguments
*/
public static void main(String args[])
{
System.out.println("OpenDis4Examples.EspduSender started... send " + NUMBER_TO_SEND + " ESPDUs, initial index=0");
/**
* an entity state pdu
*/
EntityStatePdu espdu = new EntityStatePdu();
MulticastSocket socket = null; // must be initialized, even if null
DisTime disTime = DisTime.getInstance(); // TODO explain
int alternator = -1;
// ICBM coordinates for my office
double lat = 36.595517;
double lon = -121.877000;
// Default settings. These are used if no system properties are set.
// If system properties are passed in, these are over ridden.
int port = DEFAULT_MULTICAST_PORT;
NetworkMode mode = NetworkMode.BROADCAST;
InetAddress destinationIp = null; // must be initialized, even if null
try {
destinationIp = InetAddress.getByName(DEFAULT_MULTICAST_ADDRESS);
} catch (UnknownHostException e) {
System.out.println(e + " Cannot create multicast address");
System.exit(0);
}
// All system properties, passed in on the command line via -Dattribute=value
Properties systemProperties = System.getProperties();
// IP address we send to
String destinationIpString = systemProperties.getProperty("destinationIp");
// Port we send to, and local port we open the socket on
String portString = systemProperties.getProperty("port");
// Network mode: unicast, multicast, broadcast
String networkModeString = systemProperties.getProperty("networkMode"); // unicast or multicast or broadcast
// Set up a socket to send information
try {
// Port we send to
if (portString != null)
{
System.out.println("Using systemProperties port=" + portString);
port = Integer.parseInt(portString);
}
socket = new MulticastSocket(port);
// Where we send packets to, the destination IP address
if (destinationIpString != null)
{
destinationIp = InetAddress.getByName(destinationIpString);
}
// Type of transport: unicast, broadcast, or multicast
// TODO convert to String constants
if (networkModeString != null) {
if (networkModeString.equalsIgnoreCase("unicast"))
{
mode = NetworkMode.UNICAST;
}
else if (networkModeString.equalsIgnoreCase("broadcast")) {
mode = NetworkMode.BROADCAST;
}
else if (networkModeString.equalsIgnoreCase("multicast")) {
mode = NetworkMode.MULTICAST;
if (!destinationIp.isMulticastAddress())
{
throw new RuntimeException("Sending to multicast address, but destination address " + destinationIp.toString() + "is not multicast");
}
// socket.joinGroup(destinationIp); // deprecated, TODO select correct NetworkInterface
// =======================================================================
// updated approach using NetworkInterface
NetworkInterface networkInterface = NetworkInterface.getByInetAddress(destinationIp);
if (networkInterface != null)
System.out.println("networkInterface=" + networkInterface.getDisplayName()); // typically null if loopback
SocketAddress localMulticastSocketAddress = new InetSocketAddress(destinationIp, DEFAULT_MULTICAST_PORT);
MulticastSocket multicastSocket = new MulticastSocket(DEFAULT_MULTICAST_PORT);
multicastSocket.joinGroup(localMulticastSocketAddress, networkInterface);
// =======================================================================
}
} // end networkModeString
}
catch (IOException | RuntimeException e)
{
System.out.println("Unable to initialize networking. Exiting.");
System.out.println(e);
System.exit(-1);
}
// Initialize values in the Entity State PDU object. The exercise ID is
// a way to differentiate between different virtual worlds on one network.
// Note that some values (such as the PDU type and PDU family) are set
// automatically when you create the ESPDU.
espdu.setExerciseID((short) 1);
// The EID is the unique identifier for objects in the world. This
// EID should match up with the ID for the object specified in the
// VMRL/x3d/virtual world.
EntityID entityID = espdu.getEntityID();
entityID.setSite(1); // 0 is apparently not a valid site number, per the spec
entityID.setApplication(1);
entityID.setEntity(2);
// Set the entity type. SISO has a big list of enumerations, so that by
// specifying various numbers we can say this is an M1A2 American tank,
// the USS Enterprise, and so on. We'll make this a tank. There is a
// separate project elsehwhere in this project that implements DIS
// enumerations in C++ and Java, but to keep things simple we just use
// numbers here.
EntityType entityType = espdu.getEntityType();
entityType.setEntityKind((short) 1); // Platform (vs lifeform, munition, sensor, etc.)
entityType.setCountry(225); // USA
entityType.setDomain((short) 1); // Land (vs air, surface, subsurface, space)
entityType.setCategory((short) 1); // Tank
entityType.setSubcategory((short) 1); // M1 Abrams
entityType.setSpec((short) 3); // M1A2 Abrams
Set<InetAddress> broadcastAddresses;
// Loop through sending N ESPDUs
try
{
System.out.println("Sending " + NUMBER_TO_SEND + " ESPDU packets to " + destinationIp.toString());
for (int index = 0; index < NUMBER_TO_SEND; index++) {
// DIS time is a pain in the uh, neck. DIS time units are 2^31-1 units per
// hour, and time is set to DIS time units from the top of the hour.
// This means that if you start sending just before the top of the hour
// the time units can roll over to zero as you are sending. The receivers
// (escpecially homegrown ones) are often not able to detect rollover
// and may start discarding packets as dupes or out of order. We use
// an NPS timestamp here, hundredths of a second since the start of the
// year. The DIS standard for time is often ignored in the wild; I've seen
// people use Unix time (seconds since 1970) and more. Or you can
// just stuff idx into the timestamp field to get something that is monotonically
// increasing.
// Note that timestamp is used to detect duplicate and out of order packets.
// That means if you DON'T change the timestamp, many implementations will simply
// discard subsequent packets that have an identical timestamp. Also, if they
// receive a PDU with an timestamp lower than the last one they received, they
// may discard it as an earlier, out-of-order PDU. So it is a good idea to
// update the timestamp on ALL packets sent.
// An alterative approach: actually follow the standard. It's a crazy concept,
// but it might just work.
int timestamp = disTime.getDisAbsoluteTimestamp();
espdu.setTimestamp(timestamp);
// Set the position of the entity in the world. DIS uses a cartesian
// coordinate system with the origin at the center of the earth, the x
// axis out at the equator and prime meridian, y out at the equator and
// 90 deg east, and z up and out the north pole. To place an object on
// the earth's surface you also need a model for the shape of the earth
// (it's not a sphere.) All the fancy math necessary to do this is in
// the SEDRIS SRM package. There are also some one-off formulas for
// doing conversions from, for example, lat/lon/altitude to DIS coordinates.
// Here we use those one-off formulas.
// Modify the position of the object. This will send the object a little
// due east by adding some to the longitude every iteration. Since we
// are on the Pacific coast, this sends the object east. Assume we are
// at zero altitude. In other worlds you'd use DTED to determine the
// local ground altitude at that lat/lon, or you'd just use ground clamping.
// The x and y values will change, but the z value should not.
//lon = lon + (double)((double)idx / 100000.0);
//System.out.println("lla=" + lat + "," + lon + ", 0.0");
double direction = Math.pow((double) (-1.0), (double) (index));
lon = lon + (direction * 0.00006);
System.out.println(lon);
double disCoordinates[] = CoordinateConversions.getXYZfromLatLonDegrees(lat, lon, 1.0);
Vector3Double location = espdu.getEntityLocation();
location.setX(disCoordinates[0]);
location.setY(disCoordinates[1]);
location.setZ(disCoordinates[2]);
System.out.println("lat, lon:" + lat + ", " + lon);
System.out.println("DIS coord:" + disCoordinates[0] + ", " + disCoordinates[1] + ", " + disCoordinates[2]);
// Optionally, we can do some rotation of the entity
/*
Orientation orientation = espdu.getEntityOrientation();
float psi = orientation.getPsi();
psi = psi + idx;
orientation.setPsi(psi);
orientation.setTheta((float)(orientation.getTheta() + idx /2.0));
*/
// You can set other ESPDU values here, such as the velocity, acceleration,
// and so on.
// Marshal out the espdu object to a byte array, then send a datagram
// packet with that data in it.
ByteArrayOutputStream baos = new ByteArrayOutputStream();
DataOutputStream dos = new DataOutputStream(baos);
espdu.marshal(dos);
FirePdu fire = new FirePdu();
byte[] fireArray = fire.marshal();
// The byte array here is the packet in DIS format. We put that into a
// datagram and send it.
byte[] data = baos.toByteArray();
broadcastAddresses = getBroadcastAddresses();
Iterator iterator = broadcastAddresses.iterator();
while (iterator.hasNext())
{
InetAddress broadcast = (InetAddress) iterator.next();
System.out.println("Sending broadcast datagram packet to " + broadcast);
DatagramPacket packet = new DatagramPacket(data, data.length, broadcast, port);
socket.send(packet);
// TODO experiment with these! 8)
packet = new DatagramPacket(fireArray, fireArray.length, broadcast, port); // alternate
socket.send(packet);
}
// Send every 1 sec. Otherwise all this will be all over in a fraction of a second.
Thread.sleep(1000); // msec
location = espdu.getEntityLocation();
System.out.println("Espdu #" + index + " EID=[" + entityID.getSite() + "," + entityID.getApplication() + "," + entityID.getEntity() + "]");
System.out.println(" DIS coordinates location=[" + location.getX() + "," + location.getY() + "," + location.getZ() + "]");
double c[] = {location.getX(), location.getY(), location.getZ()};
double lla[] = CoordinateConversions.xyzToLatLonDegrees(c);
// debug: System.out.println(" Location (lat/lon/alt): [" + lla[0] + ", " + lla[1] + ", " + lla[2] + "]");
}
}
catch (IOException | InterruptedException e)
{
System.out.println("Problem with OpenDis4Examples.EspduSender, see exception trace:");
System.out.println(e);
}
}
/**
* A number of sites get all snippy about using 255.255.255.255 for a
* broadcast address; it trips their security software and they kick you off
* their network. (Comcast, NPS.) This determines the broadcast address for
* all connected interfaces, based on the IP and subnet mask. If you have a
* dual-homed host it will return a broadcast address for both. If you have
* some VMs running on your host this will pick up the addresses for those
* as well--e.g. running VMWare on your laptop with a local IP this will also
* pick up a 192.168 address assigned to the VM by the host OS.
*
* @return set of all broadcast addresses
*/
public static Set<InetAddress> getBroadcastAddresses()
{
Set<InetAddress> broadcastAddresses = new HashSet<>();
Enumeration interfaces;
try {
interfaces = NetworkInterface.getNetworkInterfaces();
while (interfaces.hasMoreElements())
{
NetworkInterface anInterface = (NetworkInterface) interfaces.nextElement();
if (anInterface.isUp())
{
Iterator iterator = anInterface.getInterfaceAddresses().iterator();
while (iterator.hasNext())
{
InterfaceAddress anAddress = (InterfaceAddress) iterator.next();
if ((anAddress == null || anAddress.getAddress().isLinkLocalAddress()))
{
continue;
}
//System.out.println("Getting broadcast address for " + anAddress);
InetAddress broadcastAddress = anAddress.getBroadcast();
if (broadcastAddress != null)
{
broadcastAddresses.add(broadcastAddress);
}
}
}
}
}
catch (SocketException e)
{
System.out.println("Problem with OpenDis4Examples.EspduSender.getBroadcastAddresses(), see exception trace:");
System.out.println(e);
}
return broadcastAddresses;
}
}